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Q: Why is it important to aerate my lake during the summer? – Eric in Texas

A: Though the hottest days of summer are nearly behind us, your pond or lake still needs proper aeration – especially as we approach fall, when temperatures shift and your pond water will turn over. An aerated pond is a healthy pond, and a healthy pond is one you’ll enjoy all year long.

Why Aerate?

Ponds and lakes go through two stages of life: Stage 1, when the pond has just been excavated and Stage 2, when the pond has had a chance to become established. During Stage 1, which may only last a year, the pond is virtually nutrient-free. It has little or no leaf and plant debris, the fish have produced little waste and the environment has leached almost nothing into the water. It’s like the honeymoon stage of your pond – all the beauty with little maintenance.

After a season or two, the pond enters into Stage 2. Nutrients, like leaves, plants, fish waste and plant fertilizers, build up in the pond. You’ll start to see large amounts of algae and weed growth. Under the surface, the water column becomes murky with debris; at the bottom of the pond, muck will start to develop. This decomposing organic waste adds even more nutrients to the water – which can cause even more algae and weed growth. Talk about a vicious cycle!

At the same time, all those decomposing nutrients create a rise in toxic gas levels. Ammonia and nitrites build up in the water while the oxygen level plummets, especially in the deeper depths of the pond. Because ponds without aeration can become thermally stratified, the toxic gases created on the bottom build up in the cool water underneath. A change in temperature, a heavy rain or sometimes even high winds can turn the water over allowing the toxic, oxygen-deprived water at the bottom to mix into the top layer leaving your fish without oxygen and causing a fish kill.

The Solution

Many pond owners will turn to fountain aeration or surface aerators to churn the water. While fountains are aesthetically pleasing, they will only draw surface water, leaving the bottom of the pond uncirculated and doing nothing to eliminate toxic gases underneath.

A bottom bubbler, however, will circulate the entire water column from the bottom up and eliminate the thermal layers that form in the pond or lake. In a permanent state of motion, the action caused by the bubbler will continuously vent gasses and provide oxygen to the bottom sediments, allowing the beneficial bacteria to break down the toxic gasses and muck and give off a little oxygen in return.

Cool! I never thought that aeration is important to ponds. I have a question though, we have a small fish pond in our backyard (just for decoration and not for business purposes) and I’ve notice some algae have infested in it. A friend of mine suggested that I use a pond dye to prevent it from growing in numbers, but I’m not too sure about its effect for the fishes. Should I or is there a better alternative?

Hi Sophia – I would recommend using Pond Dye PLUS. Not only will it shade your pond, it also has beneficial bacteria to reduce the amount of nutrients in the pond. Excess nutrients feed algae blooms. Your fish will be just fine with the use of pond dye.

When do you stop feeding cat fish in the fall, and when do you start again in the spring?
what is the difference in cost to dye my lake with a liquid dye or the packets of dye that you throw into the water.
I bought a lake & beach rake from you with a floater. It is just the thing for removing duck weed from the water. What is the best thing to use to kill duck weed.I used diauron,I am not sure of the outcome yet
Carl Quayle

As the water temperatures begin to drop in the fall the catfish will also begin to eat less and less until eventually they won’t have much of an appetite at all. Once this happens, stop feeding them. Usually this happens when water temperatures start to go below 50 degrees Fahrenheit.

We have a 1 acre pond stocked with bass, bluegill and a few catfish. Your comments about the “honeymoon stage” of pond management are right on! The third year we had our pond it became murky, had several algae blooms and sometimes had an unpleasant odor. We tried several types of chemicals all to no avail, but what finally resolved our issues was an aerator. We purchased a large aerator and we run it 24×7 365 days a year. We still use UV blocking pond dye, algae treatment and natural bacteria to aid in decomposition, but have signficantly reduced the product needed, our fish are thriving and our pond looks better every month! The investment in an aerator is something I recommend for anyone who has a pond. Don’t undersize your aerator to save a little money…our neighbors, who also have a pond did that with limited benefit. Believe me, if you invest in an appropriately sized aerator you’ll make up for the cost in reduced chemicals as well as your time and frustration before you know it!

do you have anything for smaller ponds, mine is about 800 gals. Wrote before asking what I might use/do…
water is clear but there is so much sludge(?) on rocks, etc. Falls are working fine, add water regularly, but can’t get rid of bottom ‘crud’…..
Thanks…… really enjoy your newsletter.
Do you sell pumps/filters for water spitters? Again, I am a small pond owner…….

I have a small pond 1200 gals. and purchased one of the airmax aerators. I used to have the bottom sludge even though I added water and had water fall and fountain and spitters. I used to try vacuuming to remove some of sludge. My water has never been as clear as after I started to use the aerator.

Hi Carla, Thank you for the comment on your Airmax Aeration System. We love to hear success stories about the products we carry. We’re happy that you’re happy; here’s to many more years of clear water! 🙂